docs: def update(self,
                 clearEmptyFields=True,
                 title=None,
                 description=None,
                 snippet=None,
                 tags=None,
                 phone=None,
                 access=None,
                 sortField=None,
                 sortOrder=None,
                 isViewOnly=None,
                 isInvitationOnly=None,
                 thumbnail=None):
          """
          The Update Group operation (POST only) modifies properties such as
          the group title, tags, description, sort field and order, and
          member sharing capabilities. Available only to the group
          administrators or to the administrator of the organization if the
          user is a member.
  
          Only the properties that are to be updated need to be specified in
          the request. Properties not specified will not be affected.
  
          The group ID cannot be modified.
  
          Inputs:
             title - The group title must be unique for the username, and the
                     character limit is 250.
                     Example: title=Redlands Fire Department
             description - A description of the group that can be any length.
             snippet - Snippet or summary of the group that has a character
                       limit of 250 characters.
             tags	- Tags are words or short phrases that describe the group.
                    Separate terms with commas.
             phone - Phone is the group contact information. It can be a
                     combination of letters and numbers. The character limit
                     is 250.
             access - Sets the access level for the group. private is the
                      default. Setting to org restricts group access to
                      members of your organization. If public, all users can
                      access the group.
                      Values: private | org |public
             sortField - Sets sort field for group items.
                         Values: title | owner | avgRating |
                                 numViews| created | modified
             sortOrder - Sets sort order for group items.
                         Values: asc | desc
             isViewOnly - Allows the group owner or admin to create view-only
                          groups where members are not able to share items.
                          If members try to share, view-only groups are
                          returned in the notshared response property.
                          Values: false | true
  
          """
          params = {
              "f" : "json"
          }
          if title is not None:
              params['title'] = title
          if description is not None:
              params['description'] = description
          if snippet is not None:
              params['snippet'] = snippet
          if tags is not None:
              params['tags'] = tags
          if phone is not None:
              params['phone'] = phone
          if access is not None:
              params['access'] = access
          if sortField is not None:
              params['sortField'] = sortField
          if isViewOnly is not None:
              params['isViewOnly'] = isViewOnly
          if isInvitationOnly is not None:
              params['isInvitationOnly'] = isInvitationOnly
          if clearEmptyFields is not None:
              params['clearEmptyFields'] = clearEmptyFields
          files = {}
          url = self._url + "/update"
  
          if thumbnail is not None and \
             os.path.isfile(thumbnail):
              files['thumbnail'] =thumbnail
          res = None
          if thumbnail is not None and \
             os.path.isfile(thumbnail):
              res = self._post(url=url,
                               param_dict=params,
                               files=files,
                               securityHandler=self._securityHandler,
                               proxy_url=self._proxy_url,
                               proxy_port=self._proxy_port)
              return res
          else:
              res = self._post(url=url, param_dict=params,
                                  securityHandler=self._securityHandler,
                                   proxy_url=self._proxy_url,
                                   proxy_port=self._proxy_port)
          self.__init()
          return res